This invention relates to cosmetic skin and hair care preparations containing a combination of a dialkyl carbonate and an aminoalkyl amide as active principles for improving the cosmetic properties of the keratin surface.
The function of many cosmetic preparations is to make the surface of the skin soft and smooth and the hair lustrous and easy to comb. This objective is generally achieved by the incorporation of various cosmetic oil components. Silicone oils have proved to be particularly effective and, accordingly, occupy a special position within the group of cosmetic oil components.
However, it is known that silicone oils, by virtue of their strong interfacial activity and spreading effect and their marked hydrophobia, not only are very easily absorbed by skin and hair, they are also difficult to remove completely from the keratin surface, for example by washing, with the result that they accumulate, for example build up on the hair, after repeated application. This spoils the cosmetic appearance and the effect of other treatments, for example coloring or permanent waving.
Accordingly, there has been no shortage of attempts to find active principles for improving the cosmetic properties of the keratin surface which do not have this unfavorable effect.
Dialkyl carbonates are known as cosmetic oil components, for example from WO 92/122282 A1. Their suitability for improving the feel and luster of the hair treated with them is described in DE 197 10 154 C2 and WO 97/47281 A1.
Aminoalkyl amides are known, for example, from U.S. Pat. No. 5,198,209 as cationic surfactants used in combination with silicones, anionic surfactants and N-alkyl-2-pyrrolidones as components in conditioning shampoos.
It has now surprisingly been found that not only do the conditioning properties of the two substances complement one another in the combination, the cosmetic properties of compositions containing the two components in effective quantities cannot be achieved by either of the two substances on their own. This applies in particular to the combability, feel and static charging of the hair treated with the compositions.
Accordingly, the present invention relates to cosmetic skin or hair care compositions which contain a combination of active principles for improving the cosmetic properties of the keratin surface and which contain as active principles at least (A) a dialkyl carbonate with the formula R1OC(O)OR2, in which R1 and R2 independently of one another represent linear or branched C6-22 alkyl groups, and at least (B) an aminoalkyl amide with the formula R3CONH(CH2)nxe2x80x94NR4R5, in which R3CO is a linear C6-22 acyl group, R4 and R5 independently of one another represent alkyl, hydroxyalkyl or aminoalkyl groups containing up to 6 carbon atoms or, together with the N atom, form a 5- or 6-membered ring and n is a number of 2 to 6.
Cosmetic compositions in the context of the present invention are any compositions and formulations which are suitable for applying the substances to the skin or to the hair. Suitable compositions of this type include, for example, water-free oils, gels, aerosols and stick preparations. However, they may also be water-containing preparations, for example emulsions or shaking mixtures (unstable emulsions), emulsion foams in the form of pump sprays or aerosols packs, emulsion sticks or emulsion gels.
In water-free preparations, the dialkyl carbonate (A) is preferably present in a quantity of 1 to 90% by weight while the aminoalkylamide (B) is preferably present in a quantity of 0.1 to 10% by weight. Water-free preparations may also contain other oil, fatty or wax components, solvents, propellent gases and perfumes.
The preparations according to the invention are preferably present in the form of an oil-in-water emulsion of which the oil phase contains the dialkyl carbonate (A).
The dialkyl carbonate (A) is preferably present in such emulsions in a quantity of 1 to 90% by weight, based on the oil phase, and more particularly in a quantity of 5 to 50% by weight, based on the oil phase.
The aminoalkyl amide (B) is preferably present in such emulsions in a quantity of 0.1 to 2 parts by weight per part by weight of the dialkyl carbonate. Since the aminoalkylamides are substantially insoluble in water, but contain a basic amino group capable of salt formation, they are present in the alkaline medium as a constituent of the oil component.
In a preferred embodiment, however, the compositions according to the invention contain an acid in a quantity which converts the aminoalkyl amide at least partly into a water-soluble salt. The aqueous phase of the composition should preferably assume a pH of 2 to 5 through addition of the acid.
Preferred acids are, for example, C2-6 hydroxycarboxylic acids such as, for example, glycolic acid, lactic acid, malic acid, citric acid and tartaric acid. Other basically suitable acids are acetic acid, gluconic acid, ascorbic acid and inorganic acids such as, for example, phosphoric acid, sulfuric acid or hydrochloric acid.
Of the dialkyl carbonates with the formula R1xe2x80x94Oxe2x80x94C(O)xe2x80x94Oxe2x80x94R2, the symmetrical dialkyl carbonates where R1=R2 and which are obtainable by transesterification of low molecular weight dialkyl carbonates, for example diethyl carbonate, with C6-22 alcohols are particularly suitable. A most particularly suitable product is, for example, di-n-octyl carbonate.
Other dialkyl carbonates with interesting performance properties contain branched alkyl groups. An industrially available product of this type is, for example, di-(2-hexyldecyl)-carbonate which is obtained by transesterification of diethyl carbonate with a Guerbet alcohol, 2-hexyl decanol, and which is occasionally referred to as xe2x80x9cGuerbet carbonatexe2x80x9d.
The aminoalkyl amides are obtainable on an industrial scale by amide formation from C6-22 fatty acids or esters thereof and N,N-disubstituted alkylenediamines with the formula H2Nxe2x80x94(CH2)nxe2x80x94NR4R5. The compounds are normally used as starting materials for the production of quaternary ammonium compounds or betaine surfactants. Dimethylaminopropyl stearamide and isostearamidopropyl morpholine are commercially available as Tego(copyright) Amid S18 (Tego Cosmetics) and Incrocromate(copyright) ISML (Croda Inc.), respectively. Other suitable aminoalkylamides are, for example, stearic acid dihydroxyethyl aminoethyl amide or myristic acid dimethyl aminopropyl amide.
Although, in principle, the compositions according to the invention can be processed with high-foaming surfactants to form emulsion-type hair shampoos and body washes, the preparations according to the invention are preferably used for the care, setting, coloring and lightening of the hair. Examples of such preparations are hair oils, hair gels, hair lotions, hair-conditioning creams and emulsions, hair treatments, hair setting emulsions and foams, coloring and lightening emulsions and permanent wave fixing lotions.
Besides the characteristic active-principle combinations, the preparations may contain the components typical of such products.
Optional components such as these are, for example, surface-active compounds, more particularly nonionic, ampholytic, zwitterionic and cationic surfactants. Suitable nonionic surfactants are, for example, products of the addition of ethylene oxide onto fatty compounds containing labile hydrogen atoms, for example onto fatty acids, fatty alcohols, fatty acid alkanolamides, fatty acid monoglycerides, sorbitan fatty acid esters, methyl glucoside fatty acid esters, castor oil, polypropylene glycols, propylene glycol monofatty acid esters and other fatty compounds. Other nonionic surfactants are the alkyl and/or alkenyl oligoglucosides, the fatty acid-N-alkyl glucamides, tri-(polyalkoxy)-alkyl phosphates and amine oxide surfactants. Suitable ampholytic surfactants are, for example, N-alkylaminocarboxylic acids; suitable zwitterionic surfactants are, for example, the betaine surfactants such as, for example, cocoalkyl dimethyl ammonium glycinate.
In another particularly preferred embodiment, the hair treatment preparations according to the invention additionally contain a surface-active quaternary ammonium, pyridinium or imidazolinium compound or a water-soluble cationic polymer in a quantity of 0.1 to 5% by weight, based on the composition.
Cationic surfactants of the quaternary ammonium, pyridinium or imidazolinium compound type are distinguished by the fact that one or two lipophilic alkyl or acyl groups containing 10 to 22 carbon atoms are attached to the nitrogen atom of a quaternary ammonium, pyridinium or imidazolinium structure. Typical examples of such quaternary ammonium surfactants are, for example, cetyl dimethyl benzyl ammonium chloride, lauryl trimethyl ammonium chloride, distearoyloxyethyl hydroxyethyl methyl ammonium chloride, cetyl pyridinium chloride or methyl-2-stearyl-3-stearoylamidoethyl imidazolinium methoxysulfate.
Suitable water-soluble cationic polymers are, for example, the copolymers of diallyl ammonium salts and acrylamides, quaternized vinyl pyrrolidine/vinyl imidazole polymers, condensation products of polyglycols and amines, polyethyleneimine, cationic silicone polymers, copolymers of adipic acid and dimethylaminohydroxypropyl diethylenetriamine, copolymers of acrylic acid and dimethyl diallyl ammonium chloride. Water-soluble cationic polymers such as these are commercially available, for example, under the names of Merquat(copyright) 550, Gafquat(copyright), Luviquat(copyright) and Cartaretine(copyright).
However, water-soluble derivatives of natural polymers, such as cellulose, starch, guar, chitin or proteins which are distinguished by recurring cationic groups in or on the polysaccharide or peptide chain, are also suitable. Products such as these are commercially available, for example, under the names of Polymer(copyright) JR400, Lamequat(copyright) L or Jaguar(copyright).
Besides the dialkyl carbonate, the preparations according to the invention may also contain other oil components. Although silicone oils have the disadvantages mentioned above, their additional presence in the preparations according to the invention is not ruled out. This applies in particular to low-boiling cyclic silicones, such as cyclopentasiloxane for example. However, other oil and fatty components, particularly those which do not build up on the hair, even with frequent use, are preferred.
Suitable oil components are, for example, vegetable and animal or synthetic triglyceride oils, natural or synthetic wax esters, for example jojoba oil or cetyl palmitate, paraffin oils and synthetic hydrocarbons such as, for example, 1,3-dioctyl cyclohexane, squalane, fatty acid esters, such as isopropyl myristate, butyl stearate or n-hexyl laurate and other liquid esters.
Particularly suitable oil components which show excellent care properties in hair care products in conjunction with the combination of active principles according to the invention are dialkyl ethers containing 12 to 24 carbon atoms, more particularly symmetrical di-n-alkyl ethers. A particularly preferred oil component of this type is di-n-octyl ether which is commercially available as Cetiol(copyright) OE.
Finally, the preparations according to the invention may also contain other auxiliaries and additives including, for example, antimicrobial agents, deodorizing agents, preservatives, antidandruff agents, complexing agents, buffers, dyes, opacifiers, perfumes, solvents and cosmetic skin and hair care agents such as, for example, panthenol, vitamins, sebostatic agents, UV filters.
The following Examples are intended to illustrate the invention without limiting it in any way.